A doctor will base a presumptive diagnosis on information provided by the patient and on the physical examination. The characteristic appearance of the herpes sores leaves little doubt about the diagnosis, so the typical appearance of the sores is key to the diagnosis. This appearance helps distinguish oral herpes from oral thrush, shingles, gonorrhea, and syphilis. In addition, chapped or sunburned lips can resemble oral herpes, but the tissue stain (Tzanck smear, see below) shows no virus-induced cell changes. Further testing is usually not necessary but is sometimes done.
When a herpes outbreak occurs, you can expect cold sores to take about 10–14 days to heal on average. During this time period, the virus is considered to be active, and you should be very careful to avoid direct contact between a sore and someone else. If after trying the natural remedies for herpes described above you still experience frequent recurrences, talk to your doctor for how to get rid of herpes symptoms. Sometimes immunity is suppressed due to another infection or virus, or even as a side effect of taking some medications, so be sure to rule these causes out.